{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "description": "construction invoice with materials, labor, and miscellaneous charge line items plus summary totals",
  "properties": {
    "invoiceNumber": {
      "type": "string",
      "description": "the invoice number or identifier printed on the invoice."
    },
    "materials": {
      "type": "array",
      "description": "material charge line items, each a quantity of a material or work item at a unit rate. exclude any total/summary row such as TOTAL MATERIALS.",
      "items": {
        "type": "object",
        "properties": {
          "description": {
            "type": "string",
            "description": "the material or work description exactly as printed on the line."
          },
          "quantity": {
            "type": "number",
            "description": "the billed quantity of units for the line."
          },
          "rate": {
            "type": "number",
            "description": "the price per unit for the line."
          },
          "total": {
            "type": "number",
            "description": "the line total, equal to quantity times rate."
          }
        }
      }
    },
    "labor": {
      "type": "array",
      "description": "labor charge line items, each a number of hours of a task at an hourly rate. exclude any total/summary row such as TOTAL LABOR.",
      "items": {
        "type": "object",
        "properties": {
          "description": {
            "type": "string",
            "description": "the labor task description exactly as printed on the line."
          },
          "hours": {
            "type": "number",
            "description": "the number of hours worked for the line."
          },
          "rate": {
            "type": "number",
            "description": "the hourly rate for the line."
          },
          "amount": {
            "type": "number",
            "description": "the line amount, equal to hours times rate."
          }
        }
      }
    },
    "miscellaneousCharges": {
      "type": "array",
      "description": "miscellaneous charge line items. exclude any total/summary row such as TOTAL MISCELLANEOUS.",
      "items": {
        "type": "object",
        "properties": {
          "description": {
            "type": "string",
            "description": "the miscellaneous charge description exactly as printed."
          },
          "amount": {
            "type": "number",
            "description": "the charge amount."
          }
        }
      }
    },
    "totals": {
      "type": "object",
      "description": "invoice summary totals.",
      "properties": {
        "totalMaterials": {
          "type": "number",
          "description": "the printed sum of all material line totals."
        },
        "totalLabor": {
          "type": "number",
          "description": "the printed sum of all labor line amounts."
        },
        "totalMiscellaneous": {
          "type": "number",
          "description": "the printed sum of all miscellaneous charge amounts."
        },
        "subtotal": {
          "type": "number",
          "description": "the subtotal before tax."
        },
        "taxRate": {
          "type": "number",
          "description": "the tax rate applied, expressed as a percentage number (e.g. 3.8 means 3.80%)."
        },
        "totalTax": {
          "type": "number",
          "description": "the total tax amount."
        },
        "total": {
          "type": "number",
          "description": "the grand total including tax."
        }
      }
    }
  }
}